Oil rings that have been known up to now scrape extra engine oil attached to a cylinder inner wall surface of an internal combustion engine, and form a proper oil film, to thereby prevent seizure of a piston along with an operation of the internal combustion engine. Various forms have been known for such oil rings. For example, Patent Document below describes a combined oil ring including a pair of upper and lower side rails and a spacer expander arranged therebetween. The spacer expander includes: a large number of upper pieces and lower pieces that are alternately arranged in a circumferential direction so as to be spaced apart in an axial direction and the circumferential direction; coupling pieces that respectively couple the adjacent upper pieces and lower pieces; and ear parts that are each formed so as to erect in an inner circumferential end portion of each of the upper pieces and the lower pieces, and serve to push the side rails.